Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Feb 23rd, 2014–Feb 24th, 2014

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.

Regions

South Coast.

Conservative route selection is key, especially when the sun finally pokes out and if temperatures warm as forecast.

Confidence

Fair

Weather Forecast

Synopsis: Lingering flurries are likely on Monday in the wake of a frontal system. A ridge of high pressure begins to build in resulting in clearing and drier conditions for Tuesday and Wednesday. Monday: Flurries ending early (mainly south), then cloudy with sunny breaks. The freezing level is at valley bottom. Winds are generally light. Tuesday: A mix of sun and cloud. The freezing level is around 1200-1500m with treeline temps ranging from -5 to 0. Winds are light and variable. Wednesday: A mix of sun and cloud. The freezing level jumps remains near 2500 m. Winds are light and variable.

Avalanche Summary

A number of very large (size 3-4) natural and explosive triggered slab avalanches occurred near the Coquihalla Pass on Thursday and Friday. These events were in response to rapid loading from new snowfall and strong winds and showed impressive propagation. A couple natural avalanches were also observed in the Steep Creek area off the Duffey Lake road on Friday. One of these appeared to release on relatively low angle terrain (30 degrees) and propagated very far. Check out Wayne Flann's Avalanche blog for photos.

Snowpack Summary

10-20 cm of low density new snow has fallen in the past couple days, accompanied by light to moderate winds. Previous strong winds created dense wind slabs on a variety of aspects and in cross-loaded terrain features. In the southern portion of the region up to 200 cm of settled storm snow sits on a crust/facet combination buried in mid February. In northern sections this weakness includes surface hoar and is generally down 60-100 cm. Recent snowpack tests indicate that this weak layer may be gaining strength, but professionals remain suspect. The mid and lower snowpack are generally strong and well-settled. However, basal facets and depth hoar are likely to exist in the north of the region and still deserve respect on thin rocky alpine slopes.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.